Chemistry www.tiwariacademy.in Easy Question 1: What happens when peroxydisulphuric acid is hydrolysed with water? Answer 1: Sulphuric acid and hydrogen peroxide is obtained. Question 2: Name the gases produced when water reacts with: (a) Aluminium nitride (b) Aluminium carbide. Answer 2: (a) Ammonia gas is formed (b) Methane is formed Question 3: What is meant by autoprotolysis of water? Answer 3: The self oxidation reduction of water. Question 4: Why can’t sea animals live in distilled water? Answer 4: Due to the absence of free oxygen in the distilled water. Question 5: Which cations cause hardness in water? Answer 5: Calcium and magnesium cations. Question 6: What is meant by Hydrogenation? Answer 6: The addition of hydrogen is called hydrogenation. www.tiwariacademy.com A free web support in education Chemistry www.tiwariacademy.in Question 7: What is ‘syn’ gas? Answer 7: Syn gas is a mixture of CO and H2. Average Question 1: How is hydrogen prepared: a) From water by using a reducing agent? b) In laboratory in the pure form? c) From hydrocarbon? Answer 1: a) It is usually prepared by the reaction of granulated zinc with dilute hydrochloric acid. 2𝑁𝑎 + 2𝐻2𝑂 ⟶ 2𝑁𝑎𝑂𝐻 + 𝐻2 b) By the electrolysis of water. c) 𝐶𝐻4 + 𝐻2𝑂(𝑔) ⟶ 𝐶𝑂(𝑔) + 3𝐻2(𝑔) Question 2: How does H2O2 behave as a bleaching agent? Answer 2: On decomposition it produces nascent oxygen which decolourises the colour. Question 3: Discuss the structure of common form of ice. Answer 3: Due to the formation of hydrogen bonding it produce cage like structure. Question 4: How is heavy water prepared from normal water? Answer 4: From the continuous electrolysis of water. Question 5: Write the chemical reaction to show the amphoteric nature of water. Answer 5: Acidic character: 𝑁𝐻3 + 𝐻2𝑂 ⟶ 𝑁𝐻4+ + 𝑂𝐻− Basis character: 𝐻𝐶𝑙 + 𝐻2𝑂 ⟶ 𝐻3𝑂+ + 𝐶𝑙− www.tiwariacademy.com A free web support in education Chemistry www.tiwariacademy.in Question 6: What are the advantages of using hydrogen as fuel? Answer 6:  Produce no pollution.  High calorific value.  Produces drinking water. Question 7: Name the isotopes of hydrogen. What is the importance of heavier isotopes of hydrogen? Answer 7: Deuterium and tritium. The importance of heavier isotopes of hydrogen is in nuclear reactor. Difficult Question 1: When hydrogen is passed over a black solid compound A, the products are brown metal B and a colourless liquid C .The metal B displaces Silver from Silver nitrate and reacts with dilute hydrochloric acid to give hydrogen. a) Name A, B, and C. b) Give the chemical equation involved. Answer 1: a) A is CuO, B is Cu and C is H2O. b) 𝐶𝑢𝑂 + 𝐻2 ⟶ 𝐶𝑢 + 𝐻2𝑂, 𝐶𝑢 + 2𝐴𝑔𝑁𝑂3 ⟶ 𝐶(𝑁𝑂3)2 + 2𝐴𝑔. Question 2: What do you understand by the terms? a) Hydrogenation. b) Syn gas. c) Water gas-shift reaction. Answer 2: a) The addition of hydrogen is called hydrogenation. b) The mixture of CO and H2 is known as syn gas. c) 𝐶𝑂 + 𝐻2𝑂 ⟶ 𝐶𝑂2 + 𝐻2 www.tiwariacademy.com A free web support in education